Dragshock™ / Dragshock EZ™ Suspension Demonstration
Brock's Performance president, Brock Davidson, an avid performance
enthusiast and past national championship winning rider as well as tuner,
explains how to adjust the rear suspension on his BMW S1000RR 'Christine'
for drag race use. Follow along as he explains how the rebound dampening
functions as it relates to the launch and down track acceleration between
himself and his lighter 'jockeys'.
Note: At 9/16th sag using a 95 Newton (542 lb.) spring with a 150 lb.
rider in the saddle, a rear tire pressure of 12 psi is used. Brock's weight
of around 210 lbs. suited brings the sag to 1" and a tire pressure of 18
psi is used. The bike squats a bit more than optimum, which means the
spring preload should be increased a bit, or the spring rate might need to
be increased -- BUT, the object is for this bike to be as fast as possible
with the smaller riders--not tuned for him--so only tire pressure
adjustments are made.
Slick track = more rebound dampening added, more squat for more traction.
Less tire pressure, if possible.
Sticky Track = more spring preload, less squat, more tire pressure...
although light riders tend to spin, so lower pressure is generally used.
(see Jeremy's run at beginning of video, it is very close to perfect.)
Bumpy Track = If the racing surface is exceptionally bumpy, the rebound
dampening must be reduced (example adjust from -15 clicks to -20 clicks) to
prevent high speed 'oscillation'.
Stock or Short Wheelbase Applications = Stock/Short wheelbase bikes do not
require as much 'squat', because they are not as prone to spinning.
Since more squat leads to additional traction, this can also cause stock
wheelbase bikes to wheelie. As a result, we would have a bit more static
spring pressure dialed in, with more compression dampening and less rebound
dampening (to force the front end back down as the rear rises).
Special thanks to www.dragbikelive.com for the video coverage.
Also note: This advice applies to all makes and models. The BMW S1000RR
shown was simply used as a handy example for this particular video. Spring
rates will differ between makes/models.
Visit http://www.BrocksPerformance.com for additional information,
installation instructions, information forums, and FAQ sections.
BMW S1000RR with stock swingarm beats drag car and runs a 8.75et in the 1/4 mile!
Dragbike Live was on location at the 2010 Citrus Nationals in West Palm
Beach at Palm Beach International Raceway as history was made aboard the
new BMW S1000RR. Jeremy Teasley riding for Brocks Performance ran an
incredible 8.75 elapsed time at over 163 mph aboard a BMW S 1000 RR in
Super Sport specs and thus beat a drag car too! Guys this is a stock swing
arm on the bike!